Monitoring system with power supply built therein

ABSTRACT

A monitoring system with a power supply built therein, which is capable of setting installation expenses at low cost and obtaining a stable result of monitoring for a predetermined period. The monitoring system comprises a sensor unit having sensors and a power supply incorporated therein, and a portable data logger having a communication module and a power supply built therein. Physical quantities such as vibrations, temperatures, and pressure, of an object to be monitored are detected by the sensors, followed by transmission to the portable data logger, whereby the state of operation of the object is displayed.

FIELD OF THE INVENTION

[0001] The present invention relates to a monitoring system formaintaining and inspecting valves attached to various pipe arrangements,traps such as a steam trap and a gas trap, or various facilitiesinstalled in various factories, such valves including a pressurereducing valve, a safety valve, an automatic control valve, and adirectional control check valve. The present invention relatesparticularly to a monitoring system with a built-in power supply, whichis capable of reducing expenses used to install the monitoring systemand obtaining a stable output result of monitoring.

BACKGROUND INFORMATION

[0002] Plant facilities such as various rotating machines and drivingmachines, and valves for controlling the flows of various fluids havebeen mounted in large numbers on production sites in various factories.These facilities and valves have been constantly or periodicallyinspected and monitored for their operating conditions according to thedegree of their importance in order to obtain the maximum volume ofproduction with the minimum energy of consumption and maintain themaximum quality of production.

[0003] As the conventional monitoring system, one has generally beenused which senses physical quantities such as temperatures, pressure,and vibrations to be monitored, compares each sensed value with apredetermined reference value, and observes a change in each sensedvalue with time, thereby making a decision or determination as towhether an object to be monitored normally operates or is brought into apossibility that the object will lead to a failure in near future.

[0004] In the conventional monitoring system, a commercial source usedthrough a general electrical wire or line, a photocell, that is, a solarbattery, or a thermal power-generating element or device, etc. have beenused as driving sources for a sensor unit, an arithmetic display unit,etc.

[0005] The monitoring system using the commercial source of theconventional driving sources is accompanied by a problem in that theelectrical wire is made long in distance and becomes complex, therebyincreasing its cost, a problem in that the photocell cannot obtain asufficient electromotive force at night or indoors and the electromotiveforce is reduced with smudges of the surface of a light-receiving panel,or a problem in that the thermal power-generating device cannot obtain astable electromotive force at all times.

SUMMARY OF THE INVENTION

[0006] It is therefore an object of the present invention to provide anadvanced monitoring system capable of providing less installationexpenses and obtaining a stable output result of monitoring for apredetermined period to thereby make it possible to reliably confirmoperating conditions of various facilities and valves.

[0007] According to one aspect of the present invention, there isprovided a monitoring system, comprising a sensor unit for sensing oneor plural of physical quantities such as temperatures, pressure, andvibrations, which are objects to be monitored, an arithmetic displayunit for making a decision or determination, based on the value sensedby the sensor unit, as to whether an object to be monitored normallyoperates or is brought into a possibility that the object will lead to afailure in near future, and a driving power supply incorporated in atleast one of the sensor unit, the arithmetic display unit and a couplingportion for coupling the sensor unit and the arithmetic display unit toeach other by wire or radio. Thus, a power supply is incorporated into apoint where an electrical wire is maximized in length and becomescomplex, to thereby omit the electrical wire, and a power supply isbuilt in a point where a stablest drive source is required, wherebyinstallation expenses can be reduced and a predetermined stable resultof monitoring can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a block diagram showing a first embodiment of amonitoring system with a built-in power supply, according to the presentinvention.

[0009]FIG. 2 is a block diagram illustrating a second embodiment of amonitoring system with a built-in power supply, according to the presentinvention.

[0010]FIG. 3 is a block diagram depicting an embodiment of a steamtrap-oriented monitoring system with a built-in power supply, accordingto the present invention.

[0011]FIG. 4 is an enlarged cross-sectional view of a sensor employed inthe steam trap-oriented monitoring system shown in Figure.

[0012]FIG. 5 is a cross-sectional view showing a modification of thesensor shown in FIG. 4.

DETAILED DESCRIPTION

[0013]FIG. 1 shows a monitoring system wherein a sensor unit 2 isdirectly attached to a valve, a trap I or the like to be monitored,monitoring information is collected by a remote portable data logger 3,and the detailed analysis, arithmetic operation and display or storageor the like of data are performed by a computer 4.

[0014] A method of mounting the sensor unit 2 to the trap 1 is capableof joining both to each other with a fastener such as screws or the likeor detachably mounting them to each other through a joint. When thesensor unit 2 cannot be directly mounted to an object to be monitored,the sensor unit 2 may be placed in the vicinity of the object through atransfer member corresponding to a physical quantity as an object.Alternatively, the sensor unit 2 may of course be incorporated andplaced inside the object 1 to be monitored such as the valve, trap orthe like.

[0015] The sensor unit 2 shown in FIG. 1 comprises sensors 5 and 6capable of detecting physical quantities such as pressure, temperatures,vibrations, etc., a CPU 7 for computing values detected by the sensors 5and 6 and comparing them with a reference value, a display 8 fordisplaying the result of computation by the CPU 7, a communicationmodule 9 for sending the result of computation by the CPU 7 to theportable data logger 3, and a lithium battery 10 used as a source orpower supply for driving the entire sensor unit 2.

[0016] The sensor unit 2 is capable of displaying the result ofcomputation by the CPU 7, based on the values detected by the sensors 5and 6 and confirming the state of operation of the object 1 to bemonitored on the spot. Further, the sensor unit 2 is capable of sendingthe result of computation to the remote portable data logger 3 throughthe communication module 9. When it is not necessary to cause the sensorunit 2 to display the state of operation thereof, the sensor unit 2 isalso allowed to have the function of communicating with the data logger3. Although not illustrated in the drawing, a limiter for sending asignal when the upper limits or lower limits of the values detected bythe sensors 5 and 6 exceed a predetermined set value, is incorporatedinto the sensor unit 2. Similarly, a storage unit such as a RAM, a ROMor the like is provided within the sensor unit 2 to store therein an IDnumber as an identification code for the valve or the trap 1 to bemonitored.

[0017] The present embodiment shows an example in which information canbe bidirectionally transferred between the sensor unit 2 and theportable data logger 3 by radio. Radio communications include opticalcommunications using infrared rays or the like, ultrasoniccommunications or communications using commonly-used radio waves.

[0018] The portable data logger 3 comprises a module 11 whichcommunicates with the sensor unit 2, a CPU 12, a memory 13, a display14, a module 15 which communicates with the computer 4, and a lithiumbattery 16 used as a source or power supply for driving these. Theportable data logger 3 is capable of collecting monitored data obtainedfrom a plurality of valves or traps 1 used as monitoring objects atarbitrary positions away from the objects and displaying them thereon.Alternatively, the portable data logger 3 sends the data to the computer4 to allow various detailed analyses and arithmetic operations thereof,etc. When it is unnecessary to cause the data logger 3 to display thestate of operation, the data logger 3 is allowed to have the function ofcommunicating with the computer 4 and the computer 4 may display thestate of operation.

[0019] Physical quantities such as temperatures, vibrations,conductance, etc. which indicate state quantities of the valves and thetraps 1 to be monitored, are detected by the sensors 5 and 6 and sent tothe portable data logger 3 through the communication module 9 togetherwith the ID numbers corresponding to the identification codes of eachindividual valve or steam trap 1, which have been stored in a storageunit, where monitoring data indicative of the states of operations ofthe objects to be monitored such as the large number of valves and traps1 or the like are collected, followed by transmission to the computer 4,where their analyses and arithmetic operations are performed in furtherdetails. As a result, monitoring to be effected on the objects to bemonitored is executed at all times or with the frequency correspondingto the degree of importance of the objects to be monitored. In thepresent embodiment, the communication module 9 of the sensor unit 2 andthe communication module 11 of the portable data logger 3 constitute acoupling portion.

[0020] In order to reduce the consumption of power by the sensor unit 2and increase the life of the built-in battery, an analog circuit systemlying within the sensor unit 2 is normally kept deactivated and thecommunication module 9 is kept in a received waiting state. Further, theanalog circuit system lying within the sensor unit 2 is kept incommunication upon only reception of a command from the portable datalogger 3. Under such a condition, the values detected by the sensors 5and 6 can be displayed or transmitted.

[0021] Another method of reducing the consumption of power by the sensorunit 2 is as follows: An unillustrated timer lying within the CPU 7 isutilized and only the timer is normally driven. Only when the timerpasses beyond a set time, the sensor unit 2 is energized to performsensing, and the result of sensing is stored in a memory or it is sentto the data logger 3 at the time of the sensing, whereby the powerconsumption can be reduced.

[0022] A so-called primary battery such as an alkaline battery, amercury battery or a lithium battery is suitable for a source or powersupply. Described specifically, a lithium battery such as a thionylchloride lithium battery may desirably be used. Assuming that when thepresent thionyl chloride lithium battery is used, the power per day,which is consumed or used up by each of the sensor unit, the arithmeticdisplay unit and the coupling portion, for example, is about 250 mW, thebattery is able to continue using without its replacement for aboutseven years.

[0023] A battery may be utilized in combination with a solar battery, athermal power-generating element or device or the like as the powersupply at a point having a possibility of smudges being less outdoors ora point where a predetermined quantity of heat is steadily generated.

[0024] A second embodiment is illustrated in FIG. 2. In FIG. 2, amonitoring system comprises a sensor unit 2 similar to that employed inthe embodiment shown in FIG. 1, a repeater 20 for communications, a datalogger 21 for receiving a signal sent from the repeater 20, and acomputer 4.

[0025] A communication module 22 and a source or power supply 23 areincorporated into the repeater 20. A primary battery such as a lithiumbattery or the like or a combination of a solar battery or a thermalpower-generating device and a battery may be used as the power supply23.

[0026] The data logger 21 comprises a communication module 25, a CPU 26,a module 27 which communicates with the computer 4, and a generalcommercial source 28. In the present embodiment, a communication module9 of the sensor unit 2, the communication module 22 of the repeater 20,and the communication module 25 of the data logger 21 constitute acoupling portion.

[0027] A physical quantity of an object 1 to be monitored, which hasbeen detected by the sensor unit 2, is transmitted and received by thedata logger 21 through the repeater 20, followed by transmission to thecomputer 4 through a commonly-used wire connection or infraredinterface. These information transfers are not necessarily limited toone direction. The signal can be bidirectionally transferred among them.In the present embodiment, the placement of the repeater 20 in apredetermined point makes it possible to take a system for fixedlyplacing the data logger 21 in a predetermined position.

[0028] While the present embodiment shows an example in which the powersupplies for the sensor unit 2 and the portable data logger 3 are usedas the built-in batteries, the built-in battery may be used only for thesensor unit 2 or the built-in battery may be used only for the portabledata logger 3. The portable data logger 3 is normally carried bymaintenance and inspection personnel upon working. Since the portabledata logger 3 can be charged before its carrying, a rechargeable batterymay be used in place of the built-in battery.

[0029] A monitoring system in which a steam trap 1 is intended for anobject to be monitored, is next shown in FIGS. 3 and 4.

[0030] Referring to FIG. 3, the steam trap 1 is mounted between steampiping 30 on the inlet side and drain piping 31 on the outlet side withflanges 32 and 33 interposed therebetween. The steam trap 1 allows onlysteam introduced from the steam piping 30 and a drain in a mixed fluid,of a drain obtained as condensed water of steam to flow downward towardthe drain piping 31. Where only the drain flows downward within thesteam trap 1 and the steam originally prohibited from flowing downwardflows downward, the values of vibrations developed when their fluidsflow downward, differ from each other and the values of temperatures onthe external surface of the steam trap are also different from eachother. The monitoring system performs sensing on the values of thesevibrations and temperatures through the use of a sensor 17 and monitorswhether the steam trap 1 is properly operated.

[0031] In the present embodiment, the sensor 17 and a transmitter 18 areseparated from each other and only the sensor 17 is directly attached tothe steam trap 1 used as the object to be monitored. Further, thetransmitter 18 is mounted on the steam piping 30 on the inlet sidethrough a heat insulator 34 such as glass wool. Incidentally, the sensor17 and the transmitter 18 employed in the present embodiment constitutethe sensor unit 2 shown in FIG. 1. The sensor 17 and the transmitter 18are electrically connected to each other by a cable 35. As is shown by across-sectional view in FIG. 4, the sensor 17 is attached and fixed to anut 36 for assembling the steam trap 1. A nut holder 38 is placed overthe nut 36 with a spacer 37 interposed therebetween and coupled to asensor body 39 by screws, whereby the sensor 17 is fixedly mounted onthe nut 36 of the steam trap 1. The spacer 37 and the nut holder 38 forma mounting fixed portion 24.

[0032] The sensor body 39 is made up of stainless steel and shaped inthe form of a hollow cylinder. The sensor body 39 has a plurality ofradiating fins 47 at its upper portion and is connected to thetransmitter 18 shown in FIG. 3 through a cap 48 and the cable 35. Avibration transfer bar 40 with a piezoelectric element 41 attached to anupper end of the sensor body 39 is placed within the sensor body 39while being held by a holding member 42, and a thermocouple 43 is placedat a lower end of the sensor body 39. The vibration transfer bar 40 isshaped in the form of a taper so that the diameter thereof increasesfrom bottom to top. When a lower end of the vibration transfer bar 40makes contact with an upper end of a bolt 44 paired with the nut 36,vibrations produced in the steam trap 1 are transferred to thepiezoelectric element 41 through the bolt 44. The holding member 42 ismade of a heat resistant resin and prevents heat generated in the steamtrap 1 from being transferred to the piezoelectric element 41. On theother hand, the piezoelectric element 41 is composed of lead niobate orlithium niobate high in heat resistance. A coil spring 45 is placedwithin the holding member 42 so as to urge the holding member 42downward. A code 46 is mounted to an upper portion of the piezoelectricelement 41 and passes in the cable 35 so as to be connected to thetransmitter 18 shown in FIG. 3.

[0033] The thermocouple 43 is also connected to the transmitter 18through a code 49. One, which has heretofore been used so as to becapable of measuring a high temperature of the external surface of thesteam trap 1, is used as the thermocouple 43.

[0034] The monitoring system for the steam trap 1, which is shown inFIGS. 3 and 4, detects vibrations produced in the steam trap 1 throughthe use of the piezoelectric element 41 and detects each temperature ofthe external surface of the steam trap 1 by the thermocouple 43, andtransfers it to the transmitter 18 through the cable 35. The detectedsignal is sent from the transmitter 18 to the portable data logger 3shown in FIG. 1, whereby the determination or decision as to whether thesteam trap 1 normally operates or fails to operate in the normal manner,is made as described above.

[0035] Next, the sensor 19 shown in FIG. 5 is a sensor in which themounting fixed portion 24 of the sensor 17 shown in FIG. 4 is partlymodified so as to be set as a mounting fixed portion 29. The mountingfixed portion 29 is formed at a lower end of a sensor body 50 by afemale screw portion 52 and a bolt 51 paired with a nut 36, and thesensor body 50 is threadedly inserted into an upper portion of the bolt51, whereby the sensor body 50 is fixed and attached to the steam trap1.

[0036] According to the present invention as described above, amonitoring system can be provided wherein owing to the incorporation ofa power supply in at least one of a sensor unit, an arithmetic displayunit and a coupling portion, a power supply is incorporated into a pointwhere an electrical wire is maximized in length or becomes complex, tothereby omit wiring, and a power supply is built in a point where astablest drive source is required, to thereby make it possible to reduceits installation expenses and obtain a predetermined stable result ofmonitoring.

[0037] While the present invention has been described with reference tothe illustrative embodiments, this description is not intended to beconstrued in a limiting sense. Various modifications of the illustrativeembodiments, as well as other embodiments of the present invention, willbe apparent to those skilled in the art on reference to thisdescription. It is therefore contemplated that the appended claims willcover any such modifications or embodiments as fall within the truescope of the present invention.

What is claimed is:
 1. A monitoring system, comprising: a sensor unitfor sensing at least one physical quantity to be monitored, the at leastone physical quantity corresponding to at least one of a temperature, apressure, a vibration, a sound, a conductance, a concentration, and apH; an arithmetic display unit for performing one of a determiningoperation and a deciding operation based on the at least one physicalquantity sensed by the sensor unit in order to obtain an indication ofwhether an object to be monitored is functioning according to one of astatus corresponding to a normal operation and a status corresponding toa failure in a near future; a coupling portion for coupling the sensorunit and the arithmetic display unit to each other in accordance withone of a wire medium and a radio medium; and a driving power supplyarranged in at least one of the sensor unit, the arithmetic displayunit, and the coupling portion.
 2. The monitoring system according toclaim 1, further comprising: a communication module for performing oneof a wire communication and a wireless communication in order totransmit and receive a signal between the sensor unit and the arithmeticdisplay unit.
 3. The monitoring system according to claim 1, wherein thesensor unit is directly attached to the object to be monitored.
 4. Themonitoring system according to claim 1, wherein the sensor unit ismounted in a vicinity of the object to be monitored.
 5. The monitoringsystem according to claim 1, wherein: the object to be monitoredcorresponds to one of a valve and a steam trap and includes an interiorfor allowing a fluid to pass therethrough, and the sensor unit ismounted with respect to the object to be monitored in accordance withone of a direct mounting on the object to be monitored and a mounting ina vicinity of the object to be monitored.
 6. The monitoring systemaccording to claim 1, wherein the sensor unit includes a limiter forproviding a signal when one of an upper limit value and a lower limitvalue of a value detected by the sensor unit exceeds a predetermined setvalue.
 7. The monitoring system according to claim 1, wherein the sensorunit is directly attached to a fastener including one of a bolt and anut attached to the object to be monitored.
 8. The monitoring systemaccording to claim 1, wherein: the sensor unit includes a plurality ofsensors and a communication module arranged according to a divided form,the plurality of sensors are directly attached to the object to bemonitored, and the communication module is mounted away from theplurality of sensors in a vicinity of the object to be monitored.
 9. Amonitoring system for monitoring at least one object corresponding to aphysically measurable characteristic, comprising: a sensor unit fordetecting the at least one object and including: at least one sensor, afirst processing device in communication with the at least one sensorand for producing information based on a detection operation performedby the at least one sensor, a first communication device fortransmitting the information produced by the first processing device,and a power supply; and a data collecting device for collecting theinformation produced by the first processing device and including: asecond communication device for receiving the information produced bythe first processing device, a second processing device, a memory forstoring the information produced by the first processing device, and athird communication device for transmitting the information produced bythe first processing device to another processing device, wherein thefirst communication device draws from the power supply an energy forperforming a transmission of the information produced by the firstprocessing device after the first communication device receives anactivation command.
 10. A monitoring system for monitoring at least oneobject corresponding to a physically measurable characteristic,comprising: a sensor unit for detecting the at least one object andincluding: at least one sensor, a power supply, a first processingdevice in communication with the at least one sensor and for producinginformation based on a detection operation performed by the at least onesensor, wherein the first processing device includes a timer formeasuring a predetermined time period, and a first communication devicefor transmitting the information produced by the first processingdevice, wherein the sensor unit is energized when the timer has measuredthe predetermined time period; and a data collecting device forcollecting the information produced by the first processing device andincluding: a second communication device for receiving the informationproduced by the first processing device, a second processing device, amemory for storing the information produced by the first processingdevice, and a third communication device for transmitting theinformation produced by the first processing device to anotherprocessing device.
 11. A monitoring system for monitoring at least oneobject corresponding to a physically measurable characteristic,comprising: a sensor unit for detecting the at least one object andincluding: at least one sensor, a first processing device incommunication with the at least one sensor and for producing informationbased on a detection operation performed by the at least one sensor, afirst communication device for transmitting the information produced bythe first processing device, and a power supply; a data collectingdevice for collecting the information produced by the first processingdevice and including: a second communication device for receiving theinformation produced by the first processing device, a second processingdevice, a memory for storing the information produced by the firstprocessing device, and a third communication device for transmitting theinformation produced by the first processing device to anotherprocessing device; and a repeater unit including: a fourth communicationdevice, wherein the fourth communication device receives the informationproduced by the first processing device from the first communicationdevice and transmits the information produced by the first processingdevice to the second communication device.
 12. A sensor, comprising: anelongated body including a bore concentrically aligned with alongitudinal axis of the elongated body; a cap disposed on one end ofthe elongated body; a transmitting unit coupled to the elongated bodyvia the cap; at least one sensing element disposed in the bore of theelongated body; and a transfer element for communicating informationproduced by the at least one sensing element to the transmitting unit.13. The sensor according to claim 12, wherein the elongated body isformed from stainless steel.
 14. The sensor according to claim 12,further comprising: a holding member disposed within the bore of theelongated body and including a cavity for receiving the at least onesensing element, the holding member maintaining the at least one sensingelement at a position inside the elongated body.
 15. The sensoraccording to claim 14, further comprising: a spring arranged within theelongated body for urging the holding member in a direction with respectto the at least one sensing element.
 16. The sensor according to claim12, wherein the elongated body includes a plurality of heat radiatingfins.
 17. The sensor according to claim 12, wherein the transfer elementincludes an electric cable.
 18. The sensor according to claim 12,wherein the at least one sensing element includes a vibration transferbar provided with a piezoelectric element.
 19. The sensor according toclaim 12, wherein the at least one sensing element includes athermocouple.
 20. The sensor according to claim 12, further comprising amounting fixed portion for coupling the elongated body to one of a nutand a bolt of a steam trap.
 21. The sensor according to claim 20,wherein the mounting fixed portion includes: a spacer for engagementwith the nut of the steam trap, and a nut holder for coupling theelongated body to the nut of the steam trap via the spacer.